The present invention relates to a fine composite powder material such as is suitable for use as a reinforcing material for a particle dispersion type composite material or as raw material for making sintered material, and to an apparatus and to a method for making such a material; and more particularly relates to a fine powder material the particles of which are made up in a composite structure and include extremely small ceramic particles in a matrix of metal, and to an apparatus and method for manufacturing this type of fine composite powder material.
The present invention was originally made in Japan, and the first patent application made therefor was Japanese Patent Application No. 81534/83, of which priority is being claimed in the present application; and it is hereby desired to incorporate the subject matter of that previous Japanese patent application into this specification by reference; a copy is appended to this specification.
Ceramics such as alumina, silicon nitride, tungsten carbide, and so on are far superior in heat resistance and wear resistance to metals, and therefore there have been in the past various attempts to make various structural members of various machines and devices out of composite materials in which ceramic powder particles are dispersed within a matrix of metal, as well as efforts to make materials out of sintered ceramic powder.
The problems with such composite materials made with ceramic reinforcing powder particles in matrix metal are that the reinforcing powder particles are extremely brittle, that it is difficult to uniformly disperse the reinforcing particles in the matrix metal, and that the intimacy between the reinforcing particles and the matrix metal is not always very good. Because of these problems, such composite materials are not in practice used very much, except for some tool materials such as cermet.
The problem of brittleness of the ceramic powder particles, encountered both in their use in reinforced materials and in sintered materials and in their use in sintered materials, might be thought to be solvable by using as particles small particles which themselves had a composite structure, being made of still finer ceramic particles set within a matrix of metal; but although such a substance can be conceived of in theory there has in the prior art been no practical way in which such fine composite powder particles could be made with an average particle diameter of 10 microns or less, which is a smallness which is necessary for their use as reinforcing powder particles. Therefore, up to the present, it has not been possible to manufacture a composite material or a sintered material utilizing such composite reinforcing powder particles.